Thermal-infrared technology for local and regional scale irrigation analyses in horticultural systems

Irrigated horticultural crops are typically grown in semi-arid regions having inadequate rainfall to ensure a favorable fruit production. These regions generally have limited water resources, and the diversion and consumption of irrigation water is receiving increased attention by water policy makers. National policies and federal laws have been enacted to prohibit excessive water usage and to promote efficient utilization of water resources. Although some modern farms are equipped with flow meters and soil moisture sensors, crop irrigation requirements and actual water consumption of fruit trees is challenging to measure using field devices. Thermal-infrared satellite remote sensing can be used in conjunction with physically based interpretation methods to compute actual crop evapotranspiration, biomass production and soil moisture of the root zone at the plot and regional scale. The Surface Energy Balance Algorithm for Land (SEBAL) is one of several methods that utilize thermal and short-wave information to determine Evapotranspiration (ET) and other crop parameters. SEBAL validations in ET for peach, almond and grapes (rainfed and irrigated) are demonstrated. Because of limited space-borne thermal infrared data availability, airborne measurements may need to be re-examined for operational application in regions having intense irrigation schemes and high value horticulture systems.